1. Field of the Invention
The present invention relates to an apparatus for a transmission-reception simulation test for microwave communication. The apparatus according to the present invention can be used for testing the operational characteristics of a transmitter and a receiver in the same station in a simulation manner without transmitting or receiving microwaves to communicate with a remote opposite station. The transmitter and receiver may be for digital multiplex radio communication. The test of the operational characteristics may include the checking of the error rate in the transmission, the frequency characteristic, the power levels of signals in the system, and the like.
2. Description of Related Arts
In general, in the prior art apparatus for transmission-reception simulation test for a microwave radio communication system, it has been desired that the signal power level of the testing device local frequency signal, which is generated in a local oscillator in the testing device and supplied to a frequency converters in the testing device, is enhanced in order to extend the linear proportionality range between the input signal power and the output signal power of the frequency converters so that the back-off for the operation of the frequency converters is increased. However, when the signal power level of the testing device local frequency signal is enhanced, spurious signals are apt to be generated since the testing device local frequency signal contains high harmonic components, and this causes an unfavorable situation in the prior art apparatus.